<template>
	<div class="component-upload-image">
		<div style="display: flex;flex-wrap: wrap;" v-if="!showFileList">
			<div>
				<vue-draggable v-model="fileList" chosen-class="chosen" force-fallback="true" animation="300"
					@end="handleOnEnd">
					<transition-group>
						<div v-for="item in fileList" :key="item.url" class="list-item"
							style="width: 146px; height: 146px">
							<el-image style="width: 146px; height: 146px" :src="item.url" fit="cover" />
							<div class="list-item-hover">
								<i class="el-icon-zoom-in" @click="handlePictureCardPreview({file:item.url})"></i>
								<i class="el-icon-delete" @click="handleRemove(item,fileList)"
									style="margin-left: 10px;"></i>
							</div>
						</div>
					</transition-group>
				</vue-draggable>
			</div>
			<el-upload multiple :action="uploadImgUrl" list-type="picture-card" :on-success="handleUploadSuccess"
				:before-upload="handleBeforeUpload" :limit="limit" :on-error="handleUploadError"
				:on-exceed="handleExceed" name="file" :on-remove="handleRemove" :show-file-list="showFileList"
				:headers="headers" :file-list="fileList" :on-preview="handlePictureCardPreview"
				:class="{hide: this.fileList.length >= this.limit}" ref="image-upload-new" :disabled="disabled">
				<i class="el-icon-plus"></i>
			</el-upload>
		</div>

		<el-upload multiple :action="uploadImgUrl" list-type="picture-card" :on-success="handleUploadSuccess" v-else
			:before-upload="handleBeforeUpload" :limit="limit" :on-error="handleUploadError" :on-exceed="handleExceed"
			name="file" :on-remove="handleRemove" :show-file-list="showFileList" :headers="headers"
			:file-list="fileList" :on-preview="handlePictureCardPreview"
			:class="{hide: this.fileList.length >= this.limit}" ref="image-upload" :disabled="disabled">
			<i class="el-icon-plus"></i>
		</el-upload>

		<!-- 上传提示 -->
		<div class="el-upload__tip" slot="tip" v-if="showTip">
			<div>
				请上传
				<template v-if="fileSize"> 大小不超过 <b style="color: #f56c6c">{{ fileSize }}MB</b> </template>
				<template v-if="fileType"> 格式为 <b style="color: #f56c6c">{{ fileType.join("/") }}</b> </template>
				<template v-if="height"> 宽 <b style="color: #f56c6c">{{ width }}PX</b> </template>
				<template v-if="width"> 高 <b style="color: #f56c6c">{{ height }}PX</b> </template>
				的图片
			</div>
		</div>

		<el-dialog :visible.sync="dialogVisible" title="预览" width="800" append-to-body>
			<img :src="dialogImageUrl" style="display: block; max-width: 100%; margin: 0 auto" />
		</el-dialog>
	</div>
</template>

<script>
	import {
		getToken
	} from "@/utils/auth";

	export default {
		props: {
			value: [String, Object, Array, Number],
			showFileList: {
				type: Boolean,
				default: true
			},
			// 图片数量限制
			limit: {
				type: Number,
				default: 5,
			},
			width: {
				type: Number,
				default: () => 0
			},
			height: {
				type: Number,
				default: () => 0
			},
			disabled: {
				type: Boolean,
				default: false
			},
			// 大小限制(MB)
			fileSize: {
				type: Number,
				default: 5,
			},
			// 文件类型, 例如['png', 'jpg', 'jpeg']
			fileType: {
				type: Array,
				default: () => ["png", "jpg", "jpeg"],
			},
			// 是否显示提示
			isShowTip: {
				type: Boolean,
				default: true
			}
		},
		data() {
			return {
				number: 0,
				uploadList: [],
				dialogImageUrl: "",
				dialogVisible: false,
				hideUpload: false,
				baseUrl: process.env.VUE_APP_BASE_API,
				uploadImgUrl: process.env.VUE_APP_BASE_API + "/common/upload", // 上传的图片服务器地址
				headers: {
					Authorization: "Bearer " + getToken(),
				},
				fileList: [],
				apiLoading: null
			};
		},
		watch: {
			value: {
				handler(val) {
					if (val) {
						// 首先将值转为数组
						const list = Array.isArray(val) ? val : this.value.split(',');
						// 然后将数组转为对象数组
						this.fileList = list.map(item => {
							if (typeof item === "string") {
								if (item.indexOf(this.baseUrl) === -1) {
									item = {
										name: this.baseUrl + item,
										url: this.baseUrl + item
									};
								} else {
									item = {
										name: item,
										url: item
									};
								}
							}
							return item;
						});
					} else {
						this.fileList = [];
						return [];
					}
				},
				deep: true,
				immediate: true
			}
		},
		computed: {
			// 是否显示提示
			showTip() {
				return this.isShowTip && (this.fileType || this.fileSize);
			},
		},
		methods: {
			handleOnEnd() {
				this.$emit("input", this.listToString(this.fileList));
			},
			// 删除图片
			handleRemove(file, fileList) {
				const findex = this.fileList.map(f => f.name).indexOf(file.name);
				if (findex > -1) {
					this.fileList.splice(findex, 1);
					this.$emit("input", this.listToString(this.fileList));
				}
			},
			// 上传成功回调
			handleUploadSuccess(res) {
				this.uploadList.push({
					name: res.fileName,
					url: res.fileName
				});
				if (this.uploadList.length === this.number) {
					this.fileList = this.fileList.concat(this.uploadList);
					this.uploadList = [];
					this.number = 0;
					this.$emit("input", this.listToString(this.fileList));
					if (this.apiLoading) {
						this.apiLoading.close()
					}
				}
			},
			// 上传前loading加载
			handleBeforeUpload(file) {
				return new Promise(async (resolve, reject) => {
					if (this.isShowTip) {
						const isLt = file.size / 1024 / 1024 < this.fileSize;
						if (!this.fileType.some(item => file.type.indexOf(item) != -1)) {
							this.$message.error(`文件格式不正确, 请上传${this.fileType.join("/")}图片格式文件!`);
							if (this.apiLoading) {
								this.apiLoading.close()
							}
							return reject()
						}
						if (!isLt) {
							this.$message.error(`上传头像图片大小不能超过 ${this.fileSize} MB!`);
							if (this.apiLoading) {
								this.apiLoading.close()
							}
							return reject()
						}
						let res = await new Promise((_reslove, _reject) => {
							let img = new Image();
							img.src = URL.createObjectURL(file);
							img.onload = e => {
								console.log(
									`设高:高——设宽:宽_______${this.height}:${img.height}——${this.width}:${img.width}`
								);
								if (this.width != 0 && this.height != 0) {
									if (!((this.width / this.height) == (img.width / img
											.height))) {
										this.$message.error(
											`图片比例不正确，建议上传 宽：${this.width}px,高：${this.height}px`
										);
										console.log("失败");
										if (this.apiLoading) {
											this.apiLoading.close()
										}

										return reject();
									};
								}
								_reslove();
							}
						});
					};
					this.apiLoading = this.$loading({
						lock: true,
						text: '正在上传图片，请稍候...',
						spinner: 'el-icon-loading',
						background: 'rgba(0, 0, 0, 0.7)'
					});
					this.number++;
					return resolve();
				});
			},
			// 文件个数超出
			handleExceed() {
				this.$message.error(`上传文件数量不能超过 ${this.limit} 个!`);
			},
			// 上传失败
			handleUploadError() {
				if (this.apiLoading) {
					this.apiLoading.close()
				}
				this.$message.error("上传图片失败，请重试");
			},
			// 预览
			handlePictureCardPreview(file) {
				this.dialogImageUrl = file.url;
				this.dialogVisible = true;
			},
			// 对象转成指定字符串分隔
			listToString(list, separator) {
				let strs = "";
				separator = separator || ",";
				for (let i in list) {
					strs += list[i].url.replace(this.baseUrl, "") + separator;
				}
				return strs != '' ? strs.substr(0, strs.length - 1) : '';
			}
		}
	};
</script>
<style scoped lang="scss">
	.list-item {
		position: relative;
		display: inline-block;
		overflow: hidden;
		border-radius: 8px;
		margin-right: 10px;

		.list-item-hover {
			position: absolute;
			top: 0;
			left: 0;
			right: 0;
			bottom: 0;
			background-color: rgba(0, 0, 0, 0.2);
			opacity: 0;
			transition: all .3s;
			display: flex;
			align-items: center;
			justify-content: center;

			i {
				color: #FFFFFF;
				font-size: 20px;
				cursor: pointer;
			}
		}

		&:hover .list-item-hover {
			opacity: 1
		}
	}

	// .el-upload--picture-card 控制加号部分
	::v-deep.hide .el-upload--picture-card {
		display: none;
	}

	// 去掉动画效果
	::v-deep .el-list-enter-active,
	::v-deep .el-list-leave-active {
		transition: all 0s;
	}

	::v-deep .el-list-enter,
	.el-list-leave-active {
		opacity: 0;
		transform: translateY(0);
	}
</style>
